Computer Fundamentals and System Concepts

UNICS (later UNIX) originally stood for UNiplexed Information and Computing System, a play on Multics (Multiplexed Information and Computing Service). It was not 'UNified', nor is 'UNIX Information and Calculating System' the historically accurate expansion.

Opening email attachments or messages from unknown sources is historically the most common way viruses infect computers. Email remains a primary vector for malware distribution. Installing games from CDs, uploading pictures from phones, or sending emails are not significant virus transmission methods compared to email-based attacks.

Opteron was the first 64-bit microprocessor developed by AMD for servers and workstations, introducing the AMD64 (x86-64) architecture. Athlon was originally a 32-bit processor line (with Athlon 64 released later), iMac is an Apple product, and RISC-9000 is an HP architecture.

SCSI (Small Computer System Interface) is a standard for connecting and transferring data between computers and peripheral devices, most commonly storage devices like hard drives, tape drives, and optical drives. It's a storage interface standard, not primarily used for network data transfer, keystroke measurement, or picture resolution.

Heuristic scanning engines use behavioral analysis and pattern recognition to detect unknown viruses by examining code behavior rather than just matching known signatures. This allows detection of zero-day threats.

Windows 7 minimum requirements were 1GB RAM and 16GB hard disk space for the 32-bit version. The 64-bit version required 2GB RAM but still only 16GB disk space.

The COLOSSUS (1943-1944) was the first programmable electronic computer, developed at Bletchley Park to break German Lorenz cipher codes during WWII. The ABACUS is ancient mechanical device, Difference Engine was mechanical (1837), and LISA was an Apple computer from 1983.

UNIVAC (Universal Automatic Computer) was the first computer used by the US Government, specifically by the Census Bureau in 1951. ENIAC (1946) was earlier but was a military project, not civilian government use. Apple and IBM personal computers came much later (1970s-1980s).

Second-generation computers (late 1950s to mid-1960s) replaced vacuum tubes with transistors as the primary switching component. Transistors were smaller, more reliable, generated less heat, and consumed less power. This shift enabled computers to become smaller, faster, and more commercially viable. Registers and capacitors remained as components but were not the fundamental switching technology.

COLOSSUS (1943) was the first programmable electronic computer, designed by Tommy Flowers for British code-breaking at Bletchley Park. It used vacuum tubes and was programmed via plugboards and switches to break German Lorenz cipher. ABACUS is ancient (not electronic), Difference Engine was mechanical (1830s, not programmable), and LISA was Apple's 1980s GUI computer.

UNIVAC I (Universal Automatic Computer) was the first computer used by the US Government for commercial and government data processing. The US Census Bureau acquired the first UNIVAC in 1951. ENIAC was a military research machine (not government-administration use), Apple didn't exist then, and IBM's government computers came later.

Second-generation computers (late 1950s to mid-1960s) replaced vacuum tubes with transistors as the primary switching component. Transistors were smaller, more reliable, generated less heat, and consumed less power. This shift enabled computers to become smaller, faster, and more commercially viable. Registers and capacitors remained as components but were not the fundamental switching technology.

The Intel Pentium bug (1994) was a floating-point division error in the FPU (Floating Point Unit). The processor would produce incorrect results for certain division operations due to a lookup table error in the FPU. This affected Pentium processors but not the cache, socket, or other components.